Apparatus for generating large mechanical vibrations



June 16, 1953 E. w. SMITH 2,642,545

APPARATUS FOR GENERATING LARGE MECHANICAL VIBRATIONS Filed Dec. 14. 1949 FIEE INVE R. Edward W. Sm'

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Patented June 16, 1953 UNITED" STA-"res PATENT OFFICE".

APPARATUSLEOR GENERATING. ,LAJEGE MECHANICAL VIBRATIONSI 1o Claims; I

Thepresent invention relates toapparatus for generating vibrations of large amplitudes overan extended surfacetobe'used'for the removal of liquids-held in sheetmaterials and in drying of' materials such as paper; plastics, fabrics, textiles and-the like; capable of absorbing moisturewhether from water'or" other liquids, as well as-for the-impregnation of 'materialshaving large surface areas. The deviceirrthe latter case may be applied to the impregnation of the same sort of materials and also maybe-applied to dyeing or other'treatment of paper; cloth fabric, plastics or the like in aqueous or-other'liquid solutions.

In the methods heretofore used for the removal of waterfrom paper; it has been common to pass thepaper through a calender or squeeze-rolls and this method ,hasalsobeen applied to the processing of other sheetmaterials: Theapplication of pressure for this'purpose-is not always suitable because of the actionof the pressure in compressing the sheet which may change" its characteras for instance if permanent distortion occurs by some other action on the fibers orother elements forming the sheet-material.

In the method employed in the present invention, water orother liquids; passed over or in close contact with a vibrational surface of large amplitudes; may give aremarkably highacceleration: For instance the vibration of a body at a frequency of 360 cycles per second and 4 atan amplitude of 3 2" involves a maximum accelerationofaround 500 g. or in-other words, 500 times the acceleration" of gravity. When-forces of this" nature are applied to paper for an appreciable interval, the water" is effectively-removed by actually throwing the water particles away-fromthe sheet or if the sheet isin intimate contact witha liquid; vibrating with such amplitudes, the liquid will be made-topenetrate or be forced intothesheet.

Amplitudes of of an inch at 360 cycles per second and higher are considered large amplitudes: Where the: vibrating surface haswidths of "approximately 2" feet and more; as forinstance ofsubstantiai width; for example 160 inches or wider-maybe-operatedupon with the forces above described:

Another object of the present invention is to constructa device-which can treat a sheet when continuously fed.

In the device of the present invention, I prefer toemploy comparatively low frequencies, that is in therange of about 60 cycles to approximately 500 cycles rather than in the supersonic range above 10,000 cycles and to use a balanced systemso as to eliminate the necessity of a rigid or solid base for supporting the vibratory apparatus.

Theinvention will be morefully described in the specification belowwhen taken in connection" with the drawings illustrating an embodiment of the invention in which- Figure 1 shows a perspective view of the apparatus used in the, present invention with parts shown in fragmentary section.

Figure 2 shows a detail of the magnet system for" generating the mechanical oscillations, and Figure 3' shows in section a modification of a detail of Figure 1'.

In the arrangement indicated in the figures, thevibratory surfaces are formed with large similar plates l and 2 of steel or other material having a high elastic modulus, positioned parallel with one another. These plates are supported by a series of metallic tubes 3, 3, 3, which are arranged with axes parallel to each other and which may" extend substantially the length or width of the plates.

thickness chosen in such a manner that the force applied across the diameter with, for example, a one inch linear length or other chosen unit length of the tube will cause a deflection of the, tube of an amount equal to twice the desired amplitude of vibration of the two plates. The tubes 3.; 3, 3, have attached at their top and bottomexternal surfaces base members 4, 4, which, comprise a, milled or formed, dove-tail element which fits with a tight fit in a correspondingly cut groove on the under side of the plates. The flange or tapered base members 4 extend preferably the Whole length ofthe tubes 3 and should have such a close and rigid fit that there is no looseness between the tubes and the plates when the apparatus is vibrating. This may be accomplished by the use of a forcedfit joint or by expanding the groove slightly by heat before the tube is inserted. One must be careful in this connection, however, not to put excessive The tubes 3 are chosen of .highly elastic material with diameter and wall stress upon the material of the plate since the plates l and 2 should vibrate as closely as possible in the same phase over their entire surfaces. The plates I and 2 because of the balanced system will be 180 out of phase with one another, that is, both plates I and 2 will be moving simultaneously outwards and then simultaneously inwards. While in Figure 1, three metallic tubes are shown, it will be appreciated that the present type of system may be expanded both in length and width by adding more tubes and having tubes of greater length. Between the tubes is the electromagnetic system. This comprises a set of E-shaped laminations 5, which may be secured by desirable means to the inside of the plate 5, either directly or indirectly. In Figure 1, this is done through an intermediate plate 6, to which the laminations 5 are welded, the plate 6 itself being welded or secured in a suitable way to the under side diaphragm I. The

E,-shaped laminations are stacked in alignment.

parallel to the tubes 3 and between each set of tubes a magnetic structure, as described below, is located.

A coil I (see Figure 2), is placed in the recesses of the laminations threading around the center pole elements 8. In Figure 1, the opposingmagnetio element comprises an aligned stack of plain laminations 9 which may be Welded along their stacked edges to the plate it? which in turn is secured to the support II attached to the inside of the plate 2. and the support II, are all held together as a rigid structure and are rigidly attachedto the inside of the plate 2. The magnetic structure attaching to the base 2, may however, be similar to the magnetic structure attached to the bottorn of the plate I. 1

This is shown in Figure 3 where the plates I and 2 each carry a stack of aligned E-shaped laminations 5 and I2, with coils l and I3 extending longitudinally in the slots or recesses of the laminations. When alternating current is passed through the coil I (Figure 2) or through the coils I and I3 (Figure 3), a force is set up between the armatures or across the air gaps which produces a vibration of the plates. This force is applied to the plates between each of the longitudinal tubes along a length parallel to the tubes and substantially for the whole length of the diaphragm. The vibrations so applied set The laminations 9, the plate IE,

up. vibrations in the tubes which are substantially in a direction perpendicular tothe plane of the vibratingplates 5 and 2, and thereby exert in the Walls of the tubes, a compressional and bending force which by proper choice of the character of the material of the tube and itsthickness and size with respect to the masses of the plates, may bemade to resonate at a desired resonant frequency. The vibrations of the plates i and 2 will be of a so-called piston type with the greatest linear amplitude of vibration in the region where the magnetic force is applied but with a vibration not substantially less in the region of the tubes, particularly at resonance. The plates I and 2 may be of the order of in thickness,

for example, and therefore comparatively stiff to thedevice of Figurel is often used to operate in a liquid medium, it is preferable to seal the apparatus by a seal extending all around the edges. Such a seal is indicated in Figure 1 where a soft resilient sheet I4, which may be of rubber or plastic material is held tightly against the edges of the plates I and 2 by means of bands I5 and it. A cable connection may be made through the resilient sheet I4 for supplying the coils in the E--shaped laminations: with alternating current; The ordinaryalternatingsinusoidal current will produce vibrations of the electromagnetic system of the same type and also similar vibrations of the piston acting plates in opposing phases of In the present invention, the device may be used in many different ways. It may be used for the purpose of impregnating or dyeing sheet or other materials, in which case the apparatus may be suspended in a tank filled with the liquid impregnating material and the sheet may be passed over the vibratory surfaces. The sheet may be fed into the tank downward close to one vibratory face and up close to the opposite vibratory face. The device may also be used for drying purposes and is particularly adaptable for use iii-expelling liquids from solid sheets of paper, plastics, fabrics of woven, knitted, Orother construction. The word solid in this case is used in the sense of contrast with liquids and not in relation to non-porosity of the materials.

In the use of the apparatus in connection with paper, the paper sheet in its manufacture which ordinarilyis filled with water, may be drawn-over the vibrational surfaces. i and-Zand the vibration of these surfacesagainst the Water-soaked sheets will expel the water from the sheet. For this purpose, the paper could beheld against the vibratory surface by an absorbent belt or web which would take up. the moisture thrown off vibrations comprising a pair of parallel opposed plates, a plurality of tubes, means securing each of said tubes along opposite sides thereof to the opposing faces of the plates in parallel spaced relation one to the other, and electromagnetic means positioned and acting on said plates in the region between tubes for producing periodically repeated forces along substantially the length of the plates in a perpendicular direction between said plates.

2. Apparatus for generating large mechanical vibrations comprisinga pair of parallel opposed plates having substantially unrestrained peripheral edges, a plurality of cylindricaltubes, means firmly securing said tubes to the Opposing faces of the plates in, spaced relation parallel to one edge of said plates, and electromagnetic means positioned in the spaces between tubes extendingsubstantially along their length for vibrating the plates sinusoidally in opposing phases. ,3...Apparatus for generating, large mechanical vibrations comprising a pair of parallel opposed length for vibratin the plates sinusoidally in opposin phases.

4. Apparatus for generating large mechanical vibrations comprising a pair of parallel opposed plates having substantially unrestrained peripl1- eral edges, a plurality of cylindrical tubes, means firmly securing said tubes to the opposing faces of the plates in spaced relation parallel to one edge of said plates, electromagnetic means posi tioned in the space between tubes extending su stantially along their length for vibrating the plates and a yielding flexible material hermetically sealed around the edges of the plates to keep out liquids from entering into the apparatus.

5. Apparatus for generating large mechanical vibrations comprising a pair of parallel opposed plates having substantially unrestrained peripheral edges, a plurality of cylindrical tubes, means firmly securing said tubes to the opposing faces of the plates in spaced relation parallel to one edge of said plates, and electromagnetic means positioned in the space between tubes extending substantially along their length for vibrating the plates sinusoidally in opposing phases, said electromagnetic means comprising groups of E- sha-ped laminations stacked and aligned with their edges parallel to the tubes, a coil imbedded in the recesses of the E-shaped laminations, means retaining the E-shaped laminations against the inner face of the plate, armature means also formed of a stack of laminations, and means attaching said armature means in opposed relation to the E-shaped laminations against the inner face of the opposing plate whereby when the coil is energized with alternating current, vibratory forces are produced across the magnetic circuit.

6. Apparatus for generating large mechanical vibrations comprising a pair of parallel opposed plates having a high elastic modulus and of a substantial thickness, a plurality of comparatively thin cylindrical tubes, means attached to the outer surface of said tubes at diametrically opposed positions rigidly joining said tubes to the inner sides of said plates, said tubes being arranged parallel to each other, electromagnetic means acting between the inner sides of the plates exerting forces normally thereto along a line parallel with said tubes, said electromagnetic means being positioned between adjacent tubes.

'7. Apparatus for generating large mechanical vibrations comprising a pair of parallel opposed plates having a high elastic modulus and of a substantial thickness, a plurality of comparatively thin-cylindrical tubes, means attached to the outer surface of said tube at diametrically opposed positions rigidly joining said tubes to the inner sides of said plates, said tubes being arranged parallel to each other, electromagnetic means acting between the inner sides of the plates exerting forces normally thereto along a line parallel with said tubes, said electromagnetic means being positioned between adjacent tubes, said electromagnetic means comprising an armature element attached parallel to said tubes along the inside of one plate and an electromagnetic element attached in opposed relation to the other plate, magnetic material comprising stacked groups of laininations with a coil recessed therein.

8. Apparatus for generating large mechanical vibrations comprising a pair of parallel opposed plates having a high elastic modulus and of a substantial thickness, a plurality of comparatively thin cylindrical tubes, means attached to the outer surface of said tubes at diametrically opposed positions rigidly joining said tubes to the inner sides of said plates, said tubes being ar ranged parallel to each other, electromagnetic means acting between the inner sides of the plates exerting forces normally thereto along a line parallel with said tubes, said electromagnetic means being positioned between adjacent tubes, said electromagnetic means comprising similar stacks of E-shaped laminations attached to the inner sides of said plates along a region parallel to the tubes and between adjacent tubes, said E-shaped laminations having a coil iinbedded therein for carrying alternating current.

9. Apparatus for generating large mechanical vibrations comprising a pair of parallel opposed plates having a high elastic modulus and of a substantial thickness, a plurality of comparatively thin cylindrical tubes, means attached to the outer surface of said tubes at diametrically opposed positions rigidly joining said tubes to the inner sides of plates, said tubes being arranged parallel to each other, electromagnetic means acting between the inner sides of the plates exerting forces normally thereto along a line parallel with said tubes, said electromagnetic means being positioned between adjacent tubes, said electromagnetic means comprising similar stacks of E-shaped laminations attached to the inner sides of said plates along a region parallel to the tubes and between adjacent tubes, said E- shaped laminations having a coil imbedded therein for carr ing alternating current, a sheet extending around the edges of the plates sealing the inside of the apparatus from the entrance of liquids.

10. Apparatus for generating large mechanical vibrations comprising a pair of parallel opposed plates, metallic means having a high elastic modulus of the order of steel secured to and between said plates and having contact in continuous parallel line along opposing inner faces of said plates and electromagnetic means positioned and acting on said plates in the region between said means having a high elastic modulus for producing periodically repeated forces substantially along the length of the plate in a perpendicular direction between said plates.

EDVJ'ARD W. SMITH.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,811,090 Livingston June 23, 1931 2,187,717 Weyandt Jan. 23, 1940 2,211,000 Brown Aug. 13, 1940 2,279,906 Newton Apr. 14, 1942 2,464,215 Devol Mar. 15, 1949 

